How to read such inputs ? A,1,BC,2 - c++

Question

I've started working on hackerrank/hackerearth like sites. There i've found one problem fetching input. Its easy in Java.
Consider a very simple problem of reading input and displaying it :
Flow is like :
read A
repeat A times
read X1,N1,X2,N2 ; where Xi is any string, Ni is any integer.
display X1+X2, N1+N2
i don't know how to read X1,N1,X2,N2 where X1 and X2 are strings, i've also tried but problem is that when i read first string it reads entire line for eg when i read string it supposed to be X1 but it is X1,N1,X2,N2. code that i used is
scanf("%s,%d,%s,%d", x1, &n1, x2, &n2)
thanks in advance and sorry for my bad english.
Update#1:
example lines :
3
some,123,thing,456
something,579
a,1,b,2
ab,3
hello,100,world,100
helloworld,200

Answer 1

I think you are looking for something like this:
int number_of_inputs;
std::cin >> number_of_inputs;
for (int iteration = 0; iteration < number_of_inputs; ++iteration){
int integer1, integer2;
string string1, string2, stupid_comma;
std::cin >> string1 >> stupid_comma >> integer1 >> stupid_comma >> string2 >> stupid_comma >> integer2;
std::cout << string1 << " + " << string2 << " = " << integer1+integer2 << std::endl;
}
edit2: After op provides input, my code is not correct. Check this answer: Parsing a comma-delimited std::string
edit3: alternative split method op requires:
std::vector<std::string> split(const std::string &text, char sep, int num)
{
std::vector<std::string> tokens;
std::size_t start = 0, end = 0;
int elements = 0;
while ((end = text.find(sep, start)) != std::string::npos) {
if ( elements == num) break;
tokens.push_back(text.substr(start, end - start));
start = end + 1;
elements++;
}
tokens.push_back(text.substr(start));
return tokens;
}
edit4: new code using split function:
int number_of_inputs;
std::cin >> number_of_inputs;
for (int iteration = 0; iteration < number_of_inputs; ++iteration){
std:string line;
cin >> line;
int integer1, integer2;
string string1, string2, stupid_comma;
std::vector<std::string> my_line = split(line, ',', 4);
string1 = my_line[0];
string2 = my_line[2];
integer1 = stoll(my_line[1], nullptr, 10);
integer2 = stoll(my_line[3], nullptr, 10);
std::cout << string1 << " + " << string2 << " = " << integer1+integer2 << std::endl;
}

Answer 2

Here is a solution using std::regex, even though it is longer than the accepted answer, I find it much clearer and more flexible.
#include <iostream>
#include <string>
#include <regex>
using namespace std;
struct MyPair {
string x; int n;
MyPair() {}
MyPair( const string& x, int n )
: x(x), n(n) {}
};
void parse_line( const string& str, MyPair& p1, MyPair& p2 ) {
typedef regex_iterator<string::const_iterator> re_iterator;
typedef re_iterator::value_type re_iterated;
regex re("(\\w+),(\\d+),(\\w+),(\\d+)");
re_iterator rit( str.begin(), str.end(), re );
re_iterator rend;
if ( rit != rend ) {
p1 = MyPair( (*rit)[1], stoi((*rit)[2]) );
p2 = MyPair( (*rit)[3], stoi((*rit)[4]) );
}
}
int main() {
int A = 0;
while ( A <= 0 ) {
cin >> A;
}
string line;
MyPair p1, p2;
for ( int i = 0; i < A; i++ ) {
cin >> line;
parse_line( line, p1, p2 );
cout << (p1.x + p2.x) << " " << (p1.n + p2.n) << endl;
}
}
Note that it uses features from C++11, so in order to compile it using clang++ (for instance), you should do:
clang++ -std=c++11 file.cpp -o file